What’s the deal with Mets fans booing at the All-Star Game? This time Jerry Seinfeld really wants to know.

The comedian/actor ripped those at Citi Field on Tuesday night who booed baseball’s best.

“This is one of the lowest moments of my lifetime of Mets fandom, when the Citi Field crowd was booing (players) that they see as rivals to their Mets team,” Seinfeld said in a WFAN interview Wednesday night.

“And I’m standing there, I was in shock. I was embarrassed. I thought it was horrible manners.”

Seinfeld, who owns a box at Citi Field and is a life-long Mets fan, thinks the top players in the game deserve more respect than what they received.

“These are the best players, in the game you love, that have come here to put on a show for you, and we’re booing them like 5-year-olds,” Seinfeld said. “As if there’s some sort of real animosity.”

“The American League is not the Taliban,” he added. “What are we booing Miguel Cabrera (for)? … So I was very embarrassed by that.”